Abstract
The main purpose of the paper is to show that, for each real normed space Y of infinite dimension, each number L > 0, and each at most countable set Q ⊂ ℝ, there exists a Lipschitz mapping ƒ: ℝ → Y, with constant L, whose graph has a tangent everywhere, whereas ƒ is not differentiable at any point of Q.
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Translated from Sibirskiĭ Matematicheskiĭ Zhurnal, Vol. 48, No. 4, pp. 837–847, July–August, 2007.
Original Russian Text Copyright © 2007 Ponomarev S. and Turowska M.
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Ponomarev, S., Turowska, M. Lipschitz mappings, contingents, and differentiability. Sib Math J 48, 669–677 (2007). https://doi.org/10.1007/s11202-007-0069-2
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DOI: https://doi.org/10.1007/s11202-007-0069-2